An American computer expert duped international
media on Saturday into believing Islamist kidnappers had executed a hostage
in Iraq by staging his own mock beheading on the internet.

Benjamin Vanderford, 22, said he posted the 55-second clip
on an online file-sharing network in May to draw attention to his campaign
for a seat on San Francisco's Board of Supervisors.

When his political aspirations waned, he decided to distribute
the footage on Kazaa, an online file-swapping network.

It circulated in cyberspace before crossing over to a website
operated by the Islamic Global Media Centre, which has previously carried
legitimate claims of beheadings. It was picked up and used by an international
news agency, the Associated Press, and appeared on Arab television.

"It was part of a stunt, but no one noticed it up until
now," Mr Vanderford said yesterday, after being interviewed by FBI agents.

Special Agent LaRae Quy, of the bureau's San Francisco office,
said: "We will pursue any and all legal avenues for prosecution. At this
point the matter is still under investigation."

The video showed Mr Vanderford appealing to the US to leave
Iraq. The web format was that used by an al-Qaeda ally, Abu Musab al-Zarqawi,
and was introduced by a headline that said it showed Zarqawi killing an American.
"If we don't [leave Iraq], everyone is gonna be killed in this way ...

"I have been offered for exchange for prisoners here
in Iraq," the terrified-looking man said as he rocked back and forth
in his chair with his hands tied behind his back.

The video showed a hand with a large knife apparently slicing
the neck of a limp body.

But the blood was dye, the setting was a friend's garage,
the Koran reading was a tape and the knife was held by a friend.

Mutilated bodies and sound effects were spliced from photos
on websites and the video was deliberately blurred to make it seem even more
amateur, Mr Vanderford said.

One of the main reasons for his action, an unrepentant
Mr Vanderford said, was to see how the world media would react and if they
would be fooled. "It really illustrates the potential that this kind
of thing would happen."